A blood test is a laboratory analysis performed on a blood sample that is usually extracted from a vein in the arm using a needle, or via fingerprick. Multiple tests for specific blood components (such as a glucose test or a cholesterol test) are often grouped together into one test panel called a blood panel or blood work.
Upper Air Troughs. When the height contours bend strongly to the south, (as in the diagram below), it is called a TROUGH. Strong troughs are typically preceded by stormy weather and colder air at the surface. Here is an example of a trough in an upper-level height field (red contours).
Air flow Sequence. The sequence in which incoming air flows through the upper respiratory tract is as follows: 1  Normally air enters the respiratory system through two external nares (openings of the nose) and proceeds through the nasal cavity and sinuses. 2  Air is warned, filtered, and moistened.ntroduction. The respiratory system consists of the nose, nasal cavity, pharynx, larynx, trachea, bronchial tree, and the lungs. Its primary function is the basic exchange of oxygen and carbon dioxide.